drivers/nvdimm/core.c

   1 /*
   2  * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of version 2 of the GNU General Public License as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  */
  13 #include <linux/libnvdimm.h>
  14 #include <linux/export.h>
  15 #include <linux/module.h>
  16 #include <linux/device.h>
  17 #include <linux/ctype.h>
  18 #include <linux/ndctl.h>
  19 #include <linux/mutex.h>
  20 #include <linux/slab.h>
  21 #include "nd-core.h"
  22 #include "nd.h"
  23
  24 LIST_HEAD(nvdimm_bus_list);
  25 DEFINE_MUTEX(nvdimm_bus_list_mutex);
  26 static DEFINE_IDA(nd_ida);
  27
  28 void nvdimm_bus_lock(struct device *dev)
  29 {
  30         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
  31
  32         if (!nvdimm_bus)
  33                 return;
  34         mutex_lock(&nvdimm_bus->reconfig_mutex);
  35 }
  36 EXPORT_SYMBOL(nvdimm_bus_lock);
  37
  38 void nvdimm_bus_unlock(struct device *dev)
  39 {
  40         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
  41
  42         if (!nvdimm_bus)
  43                 return;
  44         mutex_unlock(&nvdimm_bus->reconfig_mutex);
  45 }
  46 EXPORT_SYMBOL(nvdimm_bus_unlock);
  47
  48 bool is_nvdimm_bus_locked(struct device *dev)
  49 {
  50         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
  51
  52         if (!nvdimm_bus)
  53                 return false;
  54         return mutex_is_locked(&nvdimm_bus->reconfig_mutex);
  55 }
  56 EXPORT_SYMBOL(is_nvdimm_bus_locked);
  57
  58 u64 nd_fletcher64(void *addr, size_t len, bool le)
  59 {
  60         u32 *buf = addr;
  61         u32 lo32 = 0;
  62         u64 hi32 = 0;
  63         int i;
  64
  65         for (i = 0; i < len / sizeof(u32); i++) {
  66                 lo32 += le ? le32_to_cpu((__le32) buf[i]) : buf[i];
  67                 hi32 += lo32;
  68         }
  69
  70         return hi32 << 32 | lo32;
  71 }
  72 EXPORT_SYMBOL_GPL(nd_fletcher64);
  73
  74 static void nvdimm_bus_release(struct device *dev)
  75 {
  76         struct nvdimm_bus *nvdimm_bus;
  77
  78         nvdimm_bus = container_of(dev, struct nvdimm_bus, dev);
  79         ida_simple_remove(&nd_ida, nvdimm_bus->id);
  80         kfree(nvdimm_bus);
  81 }
  82
  83 struct nvdimm_bus *to_nvdimm_bus(struct device *dev)
  84 {
  85         struct nvdimm_bus *nvdimm_bus;
  86
  87         nvdimm_bus = container_of(dev, struct nvdimm_bus, dev);
  88         WARN_ON(nvdimm_bus->dev.release != nvdimm_bus_release);
  89         return nvdimm_bus;
  90 }
  91 EXPORT_SYMBOL_GPL(to_nvdimm_bus);
  92
  93 struct nvdimm_bus_descriptor *to_nd_desc(struct nvdimm_bus *nvdimm_bus)
  94 {
  95         /* struct nvdimm_bus definition is private to libnvdimm */
  96         return nvdimm_bus->nd_desc;
  97 }
  98 EXPORT_SYMBOL_GPL(to_nd_desc);
  99
 100 struct nvdimm_bus *walk_to_nvdimm_bus(struct device *nd_dev)
 101 {
 102         struct device *dev;
 103
 104         for (dev = nd_dev; dev; dev = dev->parent)
 105                 if (dev->release == nvdimm_bus_release)
 106                         break;
 107         dev_WARN_ONCE(nd_dev, !dev, "invalid dev, not on nd bus\n");
 108         if (dev)
 109                 return to_nvdimm_bus(dev);
 110         return NULL;
 111 }
 112
 113 static bool is_uuid_sep(char sep)
 114 {
 115         if (sep == '\n' || sep == '-' || sep == ':' || sep == '\0')
 116                 return true;
 117         return false;
 118 }
 119
 120 static int nd_uuid_parse(struct device *dev, u8 *uuid_out, const char *buf,
 121                 size_t len)
 122 {
 123         const char *str = buf;
 124         u8 uuid[16];
 125         int i;
 126
 127         for (i = 0; i < 16; i++) {
 128                 if (!isxdigit(str[0]) || !isxdigit(str[1])) {
 129                         dev_dbg(dev, "%s: pos: %d buf[%zd]: %c buf[%zd]: %c\n",
 130                                         __func__, i, str - buf, str[0],
 131                                         str + 1 - buf, str[1]);
 132                         return -EINVAL;
 133                 }
 134
 135                 uuid[i] = (hex_to_bin(str[0]) << 4) | hex_to_bin(str[1]);
 136                 str += 2;
 137                 if (is_uuid_sep(*str))
 138                         str++;
 139         }
 140
 141         memcpy(uuid_out, uuid, sizeof(uuid));
 142         return 0;
 143 }
 144
 145 /**
 146  * nd_uuid_store: common implementation for writing 'uuid' sysfs attributes
 147  * @dev: container device for the uuid property
 148  * @uuid_out: uuid buffer to replace
 149  * @buf: raw sysfs buffer to parse
 150  *
 151  * Enforce that uuids can only be changed while the device is disabled
 152  * (driver detached)
 153  * LOCKING: expects device_lock() is held on entry
 154  */
 155 int nd_uuid_store(struct device *dev, u8 **uuid_out, const char *buf,
 156                 size_t len)
 157 {
 158         u8 uuid[16];
 159         int rc;
 160
 161         if (dev->driver)
 162                 return -EBUSY;
 163
 164         rc = nd_uuid_parse(dev, uuid, buf, len);
 165         if (rc)
 166                 return rc;
 167
 168         kfree(*uuid_out);
 169         *uuid_out = kmemdup(uuid, sizeof(uuid), GFP_KERNEL);
 170         if (!(*uuid_out))
 171                 return -ENOMEM;
 172
 173         return 0;
 174 }
 175
 176 ssize_t nd_sector_size_show(unsigned long current_lbasize,
 177                 const unsigned long *supported, char *buf)
 178 {
 179         ssize_t len = 0;
 180         int i;
 181
 182         for (i = 0; supported[i]; i++)
 183                 if (current_lbasize == supported[i])
 184                         len += sprintf(buf + len, "[%ld] ", supported[i]);
 185                 else
 186                         len += sprintf(buf + len, "%ld ", supported[i]);
 187         len += sprintf(buf + len, "\n");
 188         return len;
 189 }
 190
 191 ssize_t nd_sector_size_store(struct device *dev, const char *buf,
 192                 unsigned long *current_lbasize, const unsigned long *supported)
 193 {
 194         unsigned long lbasize;
 195         int rc, i;
 196
 197         if (dev->driver)
 198                 return -EBUSY;
 199
 200         rc = kstrtoul(buf, 0, &lbasize);
 201         if (rc)
 202                 return rc;
 203
 204         for (i = 0; supported[i]; i++)
 205                 if (lbasize == supported[i])
 206                         break;
 207
 208         if (supported[i]) {
 209                 *current_lbasize = lbasize;
 210                 return 0;
 211         } else {
 212                 return -EINVAL;
 213         }
 214 }
 215
 216 static ssize_t commands_show(struct device *dev,
 217                 struct device_attribute *attr, char *buf)
 218 {
 219         int cmd, len = 0;
 220         struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
 221         struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
 222
 223         for_each_set_bit(cmd, &nd_desc->dsm_mask, BITS_PER_LONG)
 224                 len += sprintf(buf + len, "%s ", nvdimm_bus_cmd_name(cmd));
 225         len += sprintf(buf + len, "\n");
 226         return len;
 227 }
 228 static DEVICE_ATTR_RO(commands);
 229
 230 static const char *nvdimm_bus_provider(struct nvdimm_bus *nvdimm_bus)
 231 {
 232         struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
 233         struct device *parent = nvdimm_bus->dev.parent;
 234
 235         if (nd_desc->provider_name)
 236                 return nd_desc->provider_name;
 237         else if (parent)
 238                 return dev_name(parent);
 239         else
 240                 return "unknown";
 241 }
 242
 243 static ssize_t provider_show(struct device *dev,
 244                 struct device_attribute *attr, char *buf)
 245 {
 246         struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
 247
 248         return sprintf(buf, "%s\n", nvdimm_bus_provider(nvdimm_bus));
 249 }
 250 static DEVICE_ATTR_RO(provider);
 251
 252 static int flush_namespaces(struct device *dev, void *data)
 253 {
 254         device_lock(dev);
 255         device_unlock(dev);
 256         return 0;
 257 }
 258
 259 static int flush_regions_dimms(struct device *dev, void *data)
 260 {
 261         device_lock(dev);
 262         device_unlock(dev);
 263         device_for_each_child(dev, NULL, flush_namespaces);
 264         return 0;
 265 }
 266
 267 static ssize_t wait_probe_show(struct device *dev,
 268                 struct device_attribute *attr, char *buf)
 269 {
 270         nd_synchronize();
 271         device_for_each_child(dev, NULL, flush_regions_dimms);
 272         return sprintf(buf, "1\n");
 273 }
 274 static DEVICE_ATTR_RO(wait_probe);
 275
 276 static struct attribute *nvdimm_bus_attributes[] = {
 277         &dev_attr_commands.attr,
 278         &dev_attr_wait_probe.attr,
 279         &dev_attr_provider.attr,
 280         NULL,
 281 };
 282
 283 struct attribute_group nvdimm_bus_attribute_group = {
 284         .attrs = nvdimm_bus_attributes,
 285 };
 286 EXPORT_SYMBOL_GPL(nvdimm_bus_attribute_group);
 287
 288 struct nvdimm_bus *__nvdimm_bus_register(struct device *parent,
 289                 struct nvdimm_bus_descriptor *nd_desc, struct module *module)
 290 {
 291         struct nvdimm_bus *nvdimm_bus;
 292         int rc;
 293
 294         nvdimm_bus = kzalloc(sizeof(*nvdimm_bus), GFP_KERNEL);
 295         if (!nvdimm_bus)
 296                 return NULL;
 297         INIT_LIST_HEAD(&nvdimm_bus->list);
 298         init_waitqueue_head(&nvdimm_bus->probe_wait);
 299         nvdimm_bus->id = ida_simple_get(&nd_ida, 0, 0, GFP_KERNEL);
 300         mutex_init(&nvdimm_bus->reconfig_mutex);
 301         if (nvdimm_bus->id < 0) {
 302                 kfree(nvdimm_bus);
 303                 return NULL;
 304         }
 305         nvdimm_bus->nd_desc = nd_desc;
 306         nvdimm_bus->module = module;
 307         nvdimm_bus->dev.parent = parent;
 308         nvdimm_bus->dev.release = nvdimm_bus_release;
 309         nvdimm_bus->dev.groups = nd_desc->attr_groups;
 310         dev_set_name(&nvdimm_bus->dev, "ndbus%d", nvdimm_bus->id);
 311         rc = device_register(&nvdimm_bus->dev);
 312         if (rc) {
 313                 dev_dbg(&nvdimm_bus->dev, "registration failed: %d\n", rc);
 314                 goto err;
 315         }
 316
 317         rc = nvdimm_bus_create_ndctl(nvdimm_bus);
 318         if (rc)
 319                 goto err;
 320
 321         mutex_lock(&nvdimm_bus_list_mutex);
 322         list_add_tail(&nvdimm_bus->list, &nvdimm_bus_list);
 323         mutex_unlock(&nvdimm_bus_list_mutex);
 324
 325         return nvdimm_bus;
 326  err:
 327         put_device(&nvdimm_bus->dev);
 328         return NULL;
 329 }
 330 EXPORT_SYMBOL_GPL(__nvdimm_bus_register);
 331
 332 static int child_unregister(struct device *dev, void *data)
 333 {
 334         /*
 335          * the singular ndctl class device per bus needs to be
 336          * "device_destroy"ed, so skip it here
 337          *
 338          * i.e. remove classless children
 339          */
 340         if (dev->class)
 341                 /* pass */;
 342         else
 343                 nd_device_unregister(dev, ND_SYNC);
 344         return 0;
 345 }
 346
 347 void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus)
 348 {
 349         if (!nvdimm_bus)
 350                 return;
 351
 352         mutex_lock(&nvdimm_bus_list_mutex);
 353         list_del_init(&nvdimm_bus->list);
 354         mutex_unlock(&nvdimm_bus_list_mutex);
 355
 356         nd_synchronize();
 357         device_for_each_child(&nvdimm_bus->dev, NULL, child_unregister);
 358         nvdimm_bus_destroy_ndctl(nvdimm_bus);
 359
 360         device_unregister(&nvdimm_bus->dev);
 361 }
 362 EXPORT_SYMBOL_GPL(nvdimm_bus_unregister);
 363
 364 static __init int libnvdimm_init(void)
 365 {
 366         int rc;
 367
 368         rc = nvdimm_bus_init();
 369         if (rc)
 370                 return rc;
 371         rc = nvdimm_init();
 372         if (rc)
 373                 goto err_dimm;
 374         rc = nd_region_init();
 375         if (rc)
 376                 goto err_region;
 377         return 0;
 378  err_region:
 379         nvdimm_exit();
 380  err_dimm:
 381         nvdimm_bus_exit();
 382         return rc;
 383 }
 384
 385 static __exit void libnvdimm_exit(void)
 386 {
 387         WARN_ON(!list_empty(&nvdimm_bus_list));
 388         nd_region_exit();
 389         nvdimm_exit();
 390         nvdimm_bus_exit();
 391 }
 392
 393 MODULE_LICENSE("GPL v2");
 394 MODULE_AUTHOR("Intel Corporation");
 395 subsys_initcall(libnvdimm_init);
 396 module_exit(libnvdimm_exit);